Between an engine that becomes a vibration generating source of a vehicle and a vehicle body that receives vibration, a vibration isolation device is arranged in order to suppress transmission of vibration to the vehicle body side. As the vibration isolation device, one incorporating plural liquid chambers is known for example. In this vibration isolation device, the plural liquid chambers are connected to each other through orifices, and vibration is absorbed by resistance generated when the liquid passes through the orifices in vibrating. A technology for manufacturing the vibration isolation device, particularly a technology for filling a liquid chamber with liquid, is disclosed in Patent Literature 1.
According to the technology disclosed in Patent Literature 1, first, in order to decompress the inside of a space that becomes a liquid chamber, the tip of a nozzle is inserted into a through hole that communicates with the space. In the nozzle, because an O-ring is disposed in a pedestal arranged in the vicinity of the tip of the nozzle, when the tip of the nozzle is inserted into the through hole, the O-ring is interposed and compressed between the periphery of the through hole and the pedestal. Airtight is maintained by elasticity of the O-ring, and the inside of the space is decompressed by sucking the air inside the space through the nozzle. When the inside of the space has been decompressed sufficiently, liquid is poured in to the inside of the space from the nozzle through the through hole while airtight is maintained by the O-ring, and the inside of the space is filled with the liquid. After the liquid of a required amount has been filled, the nozzle is drawn out from the through hole, the through hole is sealed by a rivet or a spherical member, and thereby the liquid chamber is to be of a sealed structure.